Video signal monitoring method, video signal monitoring device, and display device

ABSTRACT

A video signal monitoring device includes a sensor installed in a display device and configured to detect luminance and/or chromaticity in a predetermined region among regions of a video displayed on the display device, a sensing result converting unit configured to convert the detected luminance and/or chromaticity into video identification information for identifying the video, a time measuring unit configured to acquire a clock time or a period of time at or during which the video was displayed, and a sensing result reading unit configured to output the video identification information and the clock time or the period of time.

TECHNICAL FIELD

The present invention relates to a video signal monitoring method, avideo signal monitoring device, and a display device. This applicationclaims priority to Japanese Patent Application No. 2015-063638 filed onMar. 26, 2015, the entire disclosure of which is incorporated herein byreference.

BACKGROUND ART

In order to promote the replacement of an advertisement means using aconventional printing medium with another advertisement means, anadvertisement display device for displaying a video of advertisementcontent on a large-sized display device has been developed. Whenadvertisement content is displayed by this advertisement display device,it is very important for an advertisement provider, who suppliesadvertisement content and pays an advertisement fee, to confirm that theintended content is displayed as desired. It is also important for theadvertisement displayer, who displays a medium, to confirm that there isa situation in which the intended content is displayed as desired.

In order to deal with these confirmations, Patent Document 1 discloses adisplay device capable of verifying a situation where the intendedcontent is displayed as desired by providing a camera outside thedisplay device so as to record advertisement content displayed on thedisplay device.

PRIOR ART DOCUMENT

-   [Patent Document]-   [Patent Document 1]

Patent Document 1: Japanese Unexamined Patent Application, FirstPublication No. 2011-95804

DISCLOSURE OF INVENTION Problems to be Solved by the Invention

However, in the display device described in Patent Document 1, it isnecessary to install the camera outside the display device with acertain distance away therefrom, and there is a problem that themanufacturing costs of a display system are high because the camera isexpensive.

The present invention has been made in view of the above-describedpoints, and a main objective of the present invention is to provide avideo signal monitoring method and the like for solving theabove-described problem.

Means for Solving the Problem

According to the present invention for solving the above-describedproblem, there is provided a video signal monitoring method including: adetecting process in which a sensor installed in a display devicedetects luminance and/or chromaticity in a predetermined region amongregions of a video displayed on the display device; a sensing resultconverting process of converting the detected luminance and/orchromaticity into video identification information for identifying thevideo; and a sensing result reading process of outputting the videoidentification information and a clock time at which the video wasdisplayed.

Also, according to the present invention, there is provided a videosignal monitoring device including: a sensor installed in a displaydevice and configured to detect luminance and/or chromaticity in apredetermined region among regions of a video displayed on the displaydevice; a sensing result converting unit configured to convert thedetected luminance and/or chromaticity into video identificationinformation for identifying the video; a time measuring unit configuredto acquire a clock time or a period of time at or during which the videowas displayed; and a sensing result reading unit configured to outputthe video identification information and the clock time or the period oftime.

Also, according to the present invention, there is provided a displaydevice including: a sensing result converting unit configured to convertluminance and/or chromaticity detected by a sensor installed in thedisplay device in a predetermined region among regions of a videodisplayed on the display device into video identification informationfor identifying the video; a time measuring unit configured to acquire aclock time or a period of time at or during which the video wasdisplayed; and a sensing result reading unit configured to output thevideo identification information and the clock time or the period oftime.

Effects of the Invention

According to the present invention, an ID (video identificationinformation) is added to a video in order to identify the video and toindicate details of content of the video, so that it is possible toperform the verification of display content by replacing an externalcamera with a cheap small sensor without using the external camera.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic configuration diagram of a display system 1 of thepresent embodiment.

FIG. 2(a) and FIG. 2(b) are diagrams showing an ID.

FIG. 3 is a diagram showing a main configuration of the display system 1shown in FIG. 1.

FIG. 4 is a schematic configuration diagram of a display system 1A ofthe present embodiment.

FIG. 5 is a perspective view when a display device according to anembodiment of the present invention is viewed from a front side of adisplay surface.

FIG. 6 is a perspective view when the display device of FIG. 5 is viewedfrom a rear side of the display surface.

FIG. 7 is a flowchart of a process of the display system 1A of thepresent embodiment.

FIG. 8 is a schematic configuration diagram of a display system 1B ofthe present embodiment,

FIG. 9 is a perspective view when a display device according to anembodiment of the present invention is viewed from a front side of adisplay surface.

EMBODIMENTS FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described indetail with reference to the drawings. FIG. 1 is a schematicconfiguration diagram of a display system 1 of the present embodiment.

The display system 1 includes a display device 10, a signal receivingunit 11, a signal processing unit 12, a time measuring unit 13, asensing result converting unit 14, a sensing result storing unit 15, asensing result reading unit 16, and a sensor 20.

The signal receiving unit 11 externally receives a video 30 to which anID (video identification information) is added, converts the video 30into a format that can be easily processed inside the display system 1,and transmits the video 30 to the signal processing unit 12. Also, theID is an identifier having information for identifying content of thevideo and is added to the video 30 to identify the video 30.

The signal processing unit 12 performs a signal processing suitable fordisplaying the video 30 received from the signal receiving unit 11 onthe display device 10 and transmits the processed signal to the displaydevice 10.

The display device 10 displays the video 30 received from the signalprocessing unit 12. At this time, the added ID is also displayed on thescreen.

The sensor 20 is installed in the display device 10 in a state in whichthe sensor 20 is arranged to cover the ID displayed on the displaydevice 10. The sensor 20 detects change in luminance or chromaticity ofthe ID displayed on the display device 10.

FIG. 2 is a diagram showing an ID. FIG. 2(a) shows the ID when aluminance sensor is used as the sensor 20, and FIG. 2(b) shows the IDwhen a color sensor is used as the sensor 20.

As shown in FIG. 2(a), when the sensor includes only a luminance sensor,the ID is represented by only a white signal which has a series ofdisplay times of variable length and does not include the other colorinformation to indicate the content of the video. FIG. 2(a) shows astate in which the ID varies with times of 3 s (seconds), 1 s, 2 s, 1 s,and 2 s.

As shown in FIG. 2(b), when a color sensor is used as the sensor, colorinformation can be added to an ID that varies with time and colorinformation having a bit depth per display unit can be added to the ID.FIG. 2(b) shows a state in which the ID varies with times of 3 s ofwhite, 1 s of blue, 2 s of red, 1 s of white, and 2 s of green.

Identification information of an advertiser (advertisement provider) oridentification information of content can be placed in the ID. Also, theID is displayed in a predetermined size at a predetermined position,i.e., in a predetermined region among regions of a displayed video tospecify the location of the sensor 20. Also, the ID can be added to thecontent by the advertisement provider when the advertisement displayerpresents information to the advertisement provider or the ID can beadded to a video afterwards by the advertisement displayer receivingprovided content.

The sensor 20 reads the ID from the display device 10 displaying contentincluding the ID and transmits a reading result to the sensing resultconverting unit 14 as a signal indicating change in luminance orchromaticity.

The time measuring unit 13 acquires a clock time or a period of time ator during which the video with the added ID was displayed.

The sensing result converting unit 14 converts change in luminance orchromaticity received from the sensor 20 into an ID based onpredetermined rules.

Here, the conversion into the ID based on the predetermined rules refersto a process of determining a type of each of ID patterns constitutingan ID (e.g., an ID pattern or the like displayed for the initial 3 s inFIGS. 2(a) and 2(b)) on the basis of the change in luminance orchromaticity and calculating a display time of the ID patterns.

For example, the sensing result converting unit 14 can determine each IDpattern constituting the ID by determining whether the luminance orchromaticity received from the sensor 20 is within one of a plurality ofstandard ranges preset for the ID patterns.

Also, the sensing result converting unit 14 calculates a display time ofeach ID pattern. For example, when the above-described determination isperformed, the sensing result converting unit 14 can calculate thedisplay time by causing a period of time during which each ID pattern iswithin one of a plurality of preset standard ranges to correspond to aperiod of time acquired by the time measuring unit 13.

Also, the sensing result converting unit 14 sequentially transmits theID patterns constituting the ID and time signals to the sensing resultstoring unit 15 in order of measurement. Here, the time signal is adisplay time of each ID pattern constituting the ID.

A state in which the ID patterns constituting the ID are sequentiallyarranged in order of measurement is a state of the ID into whichconversion is made by the sensing result converting unit 14. That is,the sensing result converting unit 14 can convert the change inluminance or chromaticity received from the sensor 20 into the ID addedto the video 30. For example, it is possible to perform conversion intoan ID whose display time length is variable as shown in FIG. 2(a). Also,it is possible to perform conversion into an ID whose display timelength is variable and which includes color information based on aresult obtained by the color sensor as shown in FIG. 2(b).

The sensing result storing unit 15 stores the ID patterns constitutingthe ID transmitted from the sensing result converting unit 14 and thetime signals in a predetermined format in order of transmission.

Also, at this time, the sensing result storing unit 15 is consistentwith the time measuring unit 13 and also stores a clock time at whichthe ID was displayed. The consistence with the time measuring unit 13means that the time measuring unit 13 acquires a clock time at which thedisplay of the first ID pattern among the ID patterns constituting theID has been started and the sensing result storing unit 15 stores thisclock time as a clock time at which the ID was displayed on the displaydevice 10.

The sensing result reading unit 16 has a configuration capable ofreading storage content of the sensing result storing unit 15 at anytiming. The sensing result reading unit 16 receives an ID obtainedthrough conversion by the sensing result converting unit 14 by readingID patterns constituting the ID and time signals in order in which theyare stored from the sensing result storing unit 15. For example, thesensing result reading unit 16 receives the ID shown in FIG. 2 from thesensing result storing unit 15.

Also, the sensing result reading unit 16 receives a clock time at whichthe display of the ID has been started on the display device 10 from thesensing result storing unit 15.

That is, the sensing result reading unit 16 receives the ID obtainedthrough conversion by the sensing result converting unit 14 stored inthe sensing result storing unit 15 and the clock time at which the IDwas displayed on the display device 10 during a period of timemeasurement by the time measuring unit 13 and outputs a receptionresult.

As described above, the display system 1 outputs the ID obtained throughthe conversion by the sensing result converting unit 14 and the clocktime at which the ID was displayed on the display device 10, so that itis possible that the advertisement displayer indicates a clock time atwhich predetermined content displayed, to the advertisement provider.

A fixed sensor 20 is installed for the display device 10 in the abovedescription of the embodiment, but a part of the content may beconcealed in some cases. Thus, it is also possible to use a sensor thatcan be stored by predetermining the ID display time. In this case, thesensor is normally stored, but may be configured to be connected to thetime measuring unit 13 and come out at a determined time to recognizethe ID.

That is, the sensor may be installed in the display device 10 and detectthe luminance and/or chromaticity at a predetermined time after thestart of display of the video.

Next, FIG. 3 is a diagram showing a main configuration of the displaysystem 1 shown in FIG. 1.

As shown in FIG. 3, the display system 1 includes a sensor 20, a timemeasuring unit 13, a sensing result converting unit 14, and a sensingresult reading unit 16.

The sensor 20 is installed in the display device 10 and detects theluminance and/or chromaticity in a predetermined region among regions ofthe video (video 30) displayed on the display device 10. The sensor 20is a luminance sensor and detects luminance which varies with time in apredetermined region. Alternatively, the sensor 20 is a color sensor anddetects chromaticity which varies with time in a predetermined region.

The sensing result converting unit 14 converts luminance and/orchromaticity into an ID (video identification information foridentifying the video).

The time measuring unit 13 acquires a clock time or a period of time ator during which the video having the added ID was displayed.

The sensing result reading unit 16 outputs the ID and the clock time orthe period of time.

Thereby, according to the display system 1 of the present embodiment, anID (video identification information) identifying the video 30 andindicating details of content of the video 30 is added to the video 30,so that it is possible to perform the verification of display contentwithout using a camera that is necessary to be installed external, byreplacing the camera with a cheap small sensor 20. Because thecorrectness of the display content can be determined from the ID intowhich conversion is made by the sensing result converting unit 14 on thebasis of the detection result of the sensor 20 and the clock time atwhich the ID was displayed on the display device 10, it is unnecessaryto confirm a video and the time required for verification can beshortened. Thereby, it is possible to provide the display system 1 and amethod of controlling the display system 1 that can reduce themanufacturing cost and shorten the time required for verifying thecorrectness of the display content.

Although embodiments of the present invention have been described indetail above with reference to the drawings, specific configurations arenot limited to the embodiments, and changes in design, etc. may also beincluded without departing from the scope of the present invention.

For example, it is also possible to automatically provide information tothe advertisement displayer or the advertisement provider in a method ofconnecting the sensing result reading unit 16 to the cloud or the like.

When an automatic transmission means by connecting to the cloud or thelike is used in the sensing result reading unit 16, it is also possibleto automatically transmit without having the sensing result storing unit15.

Also, in the above description of the embodiment, for the sake ofconvenience, a signal used for the ID uses fixed amplitude (luminance).It is also possible to change this amplitude to further increase anamount of information. For example, by expressing 8 gradations,information of 3 bits can be added.

In the above description of the embodiment, the sensor 20 is assumed tobe installed in the display device 10 within the display system 1.However, a method of externally connecting the sensor 20 and realizingthe conversion of the sensing result converting unit 14 and the storageof the sensing result storing unit 15 by a personal computer (PC) isalso conceivable.

Next, a display system 1A obtained by embodying the display system 1will be described.

FIG. 4 is a schematic configuration diagram of a display system 1A ofthe present embodiment. In FIG. 4, the same parts as those in FIG. 1 aredenoted by the same reference signs, and a description thereof will beomitted here.

The display system 1A includes a video identification information addingdevice 100, a display device 10A, a sensor-equipped module 5 (videosignal monitoring device), and a video identification informationcomparing device 200.

The display device 10A is configured to include a signal receiving unit11, a signal processing unit 12, and a display panel 2A.

The sensor-equipped module 5 includes a sensor 20A and a sensing module5A. The sensing module 5A is configured to include a time measuring unit13, a sensing result converting unit 14, a sensing result storing unit15, and a sensing result reading unit 16.

The video identification information adding device 100 is arrangedoutside the display device 10A, adds an ID for distinguishing content tothe advertisement content displayed on the display device 10A, andtransmits the video 30 with the added ID to the signal receiving unit 11of the display device 10A. The video identification information addingdevice 100 may be a PC that transmits the video 30 to one display device10A or a server that transmits the video 30 to two or more displaydevices 10A.

Here, an arrangement for the display device 10A of the sensor-equippedmodule 5 will be described with reference to FIGS. 5 and 6.

FIG. 5 is a perspective view when the display device 10A according to anembodiment of the present invention is viewed from a front side of adisplay surface. Also, FIG. 6 is a perspective view when the displaydevice of FIG. 5 is viewed from a rear side of the display surface.

The display panel 2A in the display device 10A has a display surface 3Afor displaying the video 30 on the front surface.

The sensor 20A is arranged to cover an end region of the display surface3A of the display panel 2A (a fixed region including outermost pixels ofthe display panel 2A). Also, the sensor 20A has a connector 60A and isconnected to a connector 61A of a sensing module 5A arranged on the rearside of the display panel 2A shown in FIG. 6 via a cable 7A. Theconnector 61A is connected to the sensing result converting unit 14through the internal wiring within the sensing module 5A, and the IDdetected by the sensor 20A is input to the sensing result convertingunit 14.

The sensing module 5A can be inserted into and extracted from a slot 8formed in the display panel 2A. An insertion/extraction direction AB ofthe sensing module 5A for the slot 8 is a direction orthogonal to athickness direction W of the display panel 2A. The sensing module 5A iselectrically connected to power supply wiring within the display device10A in a state in which the sensing module 5A is inserted into the slot8, and the sensing result converting unit 14 and the like becomeoperable.

The sensing module 5A includes a connector 62A. For example, the sensingresult reading unit 16 outputs the ID result and the time information tothe video identification information comparing device 200 through a LANcable (not shown in FIG. 6) connected to the connector 62A. Of course,the sensing result reading unit 16 may perform transmission to the videoidentification information comparing device 200 according to wirelesstransmission.

Also, the sensing module 5A may be installed outside the display device10A without being inserted into the slot 8. In this case, it can beelectrically connected to power supply wiring from an external powersupply device outside the display device 10A, and the sensing resultconverting unit 14 and the like are then operable.

Also, when the display device includes a multi-display device in which aplurality of (m rows×n columns (m and n are natural numbers)) displaydevices 10A are connected in a daisy chain manner, the sensor 20A may beconfigured to be arranged at the end of the display surface 3A of thedisplay panel 2A of at least one of the (m×n) display devices.

Also, for example, a configuration in which a function of the sensingmodule 5A is installed on a function expansion module that extends afunction of the display device 10A as an open pluggable specification(OPS), and the function expansion module is inserted/extracted in themethod shown in FIG. 6 may be adopted. Also, for example, when asubstrate of a small computer such as Raspberry Pi is inserted into thedisplay device 10A, a substrate of the sensing module 5A may beinserted.

Returning to FIG. 4, the video identification information comparingdevice 200 includes, for example, a PC, and determines whether or notthe video 30 has been displayed on the display device 10A on the basisof whether the ID obtained in the sensing result reading processperformed by the sensing result reading unit 16 and the clock time atwhich the ID was displayed on the display device 10A match an ID addedto the video 30 displayed on the display device 10A by the videoidentification information adding device 100 and a scheduled displayclock time of the added ID.

Also, the sensing result reading unit 16 writes the ID obtained in thesensing result reading process and the display clock time of the ID to aUSB memory connected to the sensing result reading unit 16 by auniversal serial bus (USB) cable. On the basis of whether the written IDand the written clock time at which the ID was displayed match the IDadded to the video 30 by the video identification information addingdevice 100 and the scheduled display clock time of the added ID, thevideo identification information comparing device 200 may be configuredto determine whether or not the video 30 has been displayed on thedisplay device 10A.

Next, a control process in the display system 1A will be described. FIG.7 is a flowchart of a process of the display system 1A of the presentembodiment.

Advertisement content is input to the video identification informationadding device 100 (step S1).

The video identification information adding device 100 adds an ID fordistinguishing the advertisement content to the advertisement content(step S2).

The advertisement content (video 30) to which the ID output from thevideo identification information adding device 100 has been added isinput to the signal receiving unit 11 of the display device 10A (stepS3).

The signal processing unit 12 of the display device 10A processes thevideo 30 (step S4).

The video 30 including the advertisement content and the ID fordistinguishing the advertisement content is displayed on the displaypanel 2A of the display device 10A (step S5).

The sensor 20A detects the ID (step S6).

The sensor 20A transmits the detected ID to the sensing resultconverting unit 14 (step S7).

The sensing result converting unit 14 receives the ID detected by thesensor 20A (step S8).

The sensing result converting unit 14 converts a signal format of the IDinto a comparable signal format similar to that of an ID superimposed onoriginal advertisement content (step S9). This is assumed to be an IDresult.

The sensing result converting unit 14 adds time information from thetime measuring unit 13 to the ID result (step S10).

The sensing result storing unit 15 stores the ID result and clock timeinformation (step S11).

The sensing result reading unit 16 outputs the ID result and the clocktime information (step S12).

The video identification information comparing device 200 receives theID result and the clock time information (step S13).

The video identification information comparing device 200 compares theID added to the content by the video identification information addingdevice 100 with the ID result (step S14). Thereby, it can be confirmedwhether or not the advertisement content has been correctly displayed onthe display device 10A.

Next, a display system 1B obtained by embodying the display system 1will be described.

FIG. 8 is a schematic configuration diagram of a display system 1B ofthe present embodiment. In FIG. 8, the same parts as those in FIG. 4showing the display system 1A are denoted by the same reference signs,and a description thereof will be omitted.

The display system 1B is configured to include a video identificationinformation adding device 100, a display device 10B (display device),and a video identification information comparing device 200.

The display device 10B is configured to include a signal receiving unit11, a signal processing unit 12, a display panel 2B, and a sensingmodule 5B.

The sensing module 5B has the same configuration as the sensing module5A shown in FIG. 4 and is configured to include a time measuring unit13, a sensing result converting unit 14, a sensing result storing unit15, and a sensing result reading unit 16. Unlike the sensing module 5Ashown in FIG. 4, the sensing module 5B is incorporated in the displaydevice 10B.

Here, an arrangement for the display device 10B of a sensor 20B will bedescribed with reference to FIG. 9.

FIG. 9 is a perspective view when the display device 10B according to anembodiment of the present invention is viewed from a front side of adisplay surface.

The display panel 2B of the display device 10B has a display surface 3Bfor displaying the video 30 on the front surface.

The sensor 20B is arranged to cover an end region of the display surface3B of the display panel 2B (a fixed region including outermost pixels ofthe display panel 2B). The sensor 20B has a connector 60B and isconnected to a connector 61B of the display panel 2B shown in FIG. 9 viaa cable 7B. The connector 61B is connected to the sensing resultconverting unit 14 through the internal wiring in the display device10B, and the ID detected by the sensor 20B is input to the sensingresult converting unit 14.

The display panel 2B has a connector 62B. The sensing result readingunit 16 is connected to the video identification information comparingdevice 200 by, for example, a LAN cable (not shown in FIG. 9) connectedto the connector 62B, and outputs an ID result and a clock timeinformation to the video identification information comparing device200.

Thereby, it can be confirmed whether or not advertisement content hasbeen correctly displayed on the display device 10B.

In the display system 1A, the video signal monitoring device includingthe sensor 20A and the sensing module 5A is configured to be externallyattached to the display device 10A. Also, in the display system 1B, thesensing module 5B is inside the display device 10B, and the sensor 20Bis configured to be externally attached to the display device 10A. Incontrast to these, in the display system, the display device may beconfigured to incorporate the sensor and the sensing module.

Also, the sensing result converting process to be performed by thesensing result converting unit 14 and the sensing result reading processto be performed by the sensing result reading unit 16 in the controlsystems of the display systems 1, 1A, and 1B may be performed byrecording a program for realizing functions of the display systems 1,1A, and 1B in FIG. 1 on a computer-readable recording medium and causinga computer system to read and execute the program recorded on therecording medium. Also, the “computer system” used here is assumed toinclude an operating system (OS) and hardware such as peripheraldevices.

Also, the “computer system” is assumed to include a World Wide Web (WWW)system having a homepage providing environment (or displayingenvironment).

Also, the “computer-readable recording medium” refers to a storageapparatus including a flexible disk, a magneto-optical disc, a read onlymemory (ROM), or a portable medium such as a compact disc (CD)-ROM, ahard disk embedded in the computer system, and the like. Furthermore,the “computer-readable recording medium” is assumed to include a mediumthat holds a program for a fixed period of time, such as a volatilememory (random access memory (RAM)) inside a computer system serving asa server or a client when the program is transmitted via a network suchas the Internet or a communication circuit such as a telephone circuit.Also, the above-described program may be a program for implementing someof the above-described functions. Further, the above-described programmay be a program capable of implementing the above-described functionsin combination with a program already recorded on the computer system.

INDUSTRIAL APPLICABILITY

According to the present invention, it is possible to provide a videosignal monitoring method or the like capable of confirming whether ornot advertisement content has been correctly displayed on a videodisplay device.

REFERENCE SYMBOLS

1, 1A, 1B Display system

2A, 2B Display panel

3A, 3B Display surface

5 Sensor-equipped module

5A, 5B Sensing module

10, 10A, 10B Display device

11 Signal receiving unit

12 Signal processing unit

13 Time measuring unit

14 Sensing result converting unit

15 Sensing result storing unit

16 Sensing result reading unit

20, 20A, 20B Sensor

30 Video

100 Video identification information adding device

200 Video identification information comparing device

The invention claimed is:
 1. A video signal monitoring methodcomprising: a detecting process in which a sensor installed in a displaydevice detects at least of luminance or chromaticity in a predeterminedregion among regions of a video displayed on the display device; asensing result converting process of converting the at least one ofdetected luminance or chromaticity into video identification informationfor identifying the video; and a sensing result reading process ofoutputting the video identification information and a clock time atwhich the video was displayed.
 2. The video signal monitoring methodaccording to claim 1, further comprising: a video identificationinformation determining process of determining whether or not the videohas been displayed on the basis of whether or not the videoidentification information and the clock time obtained in the sensingresult reading process match video identification information added tothe video displayed on the display device and a scheduled display clocktime of the added video identification information, respectively.
 3. Thevideo signal monitoring method according to claim 1, wherein the sensorcomprises a luminance sensor and detects luminance that varies with timein the predetermined region.
 4. The video signal monitoring methodaccording to claim 1, wherein the sensor comprises a color sensor anddetects chromaticity that varies with time in the predetermined region.5. The video signal monitoring method according to claim 1, wherein thesensor detects the at least one of luminance or chromaticity at apredetermined period of time after a start of display of the video.
 6. Avideo signal monitoring device comprising: a sensor installed in adisplay device and configured to detect at least one of luminance orchromaticity in a predetermined region among regions of a videodisplayed on the display device; a sensing result converting unitconfigured to convert the at least one of detected luminance orchromaticity into video identification information for identifying thevideo; a time measuring unit configured to acquire a clock time or aperiod of time at or during which the video was displayed; and a sensingresult reading unit configured to output the video identificationinformation and the clock time or the period of time.
 7. A displaydevice comprising: a sensing result converting unit configured toconvert at least one of luminance or chromaticity detected by a sensorinstalled in the display device in a predetermined region among regionsof a video displayed on the display device into video identificationinformation for identifying the video; a time measuring unit configuredto acquire a clock time or a period of time at or during which the videowas displayed; and a sensing result reading unit configured to outputthe video identification information and the clock time or the period oftime.